Story by Mark Hume with Photography by Nick Didlick Salmon are the base of everything in the Pacific Northwest. Fishermen have known that intuitively for a long time, but now it has been confirmed in a set of studies from salmon ecology researchers at Simon Fraser University, in British Columbia. In one of the largest field studies on salmon in the world, Morgan Hocking, a postdoctoral fellow, and John Reynolds, the Tom Buell B.C. Leadership Chair in Salmon Conservation, looked at 50 watersheds in the Great Bear Rainforest. The region, on B.C.’s Central Coast, is a largely protected area that still holds some of the last untouched old growth forest in North America. It is mostly without roads, and the research team went there to look at how salmon runs impact watershed vegetation. What they found is that the salmon carcasses dragged out of the water by bears, wolves and other animals, change the nature of the surrounding forest. The change is so dramatic, said Mr. Reynolds in an interview, that it is possible to tell how rich a salmon run is by looking at the forest makeup along the stream. “Before we started the study I would have thought that was a real long shot. But now I think we could do that,” he said. “The impacts of salmon on plants are so radical that, even without knowing how many salmon spawn in specific streams, we can get a good idea by studying the surrounding plant life.” The study found that plants that are good at picking up nitrogen, which filters into the soil from salmon carcasses, thrived along streams with large salmon runs. Those plants that weren’t as good at absorbing those nutrients, were pushed out of the area. “The shift in...